The present invention relates to hand held clippers for trimming hair and the like. More particularly, the present invention is related to seals for sealing a gap in an electric hand held clipper housing, as well as to clippers having a seal for sealing a housing gap.
Hand held clippers for trimming and shearing hair are generally known in the art. Conventional clippers typically include a housing that contains a motor, with the motor drivingly attached to a blade assembly for trimming or cutting the hair. The blade assembly typically has a reciprocating blade that cooperates with a fixed blade to trim or clip hair. The housing may have a front opening for passing an operative portion of the fixed and moving blades. A gap generally exists between the blade assembly and the housing. This gap can have several disadvantages associated with it.
For example, the gap may be proximate the operating portion of the blades and therefore be regularly exposed to cut portions of hair. The hair cuttings can enter the clipper housing through the gap and can be harmful to operation of the clipper. Cuttings can become tangled between the moving and non-moving blade, increase friction between the two blades, and over time may even shorten the stroke of the moving blade. Hair cuttings can likewise interfere with operation of the motor and its linkage to the moving blade. Further, hair cuttings can trap dust, grease, and other debris. These and other problems with hair cuttings are particularly troublesome because hair cuttings are notoriously slow to decompose and difficult to disengage once entangled. These problems can result in the need for frequent disassembly and cleaning of clippers, and if not effectively addressed can lead to a substantially shortened clipper service life.
Some solutions to these problems have been proposed in the past. To date, however, the proposed solutions have been deficient. For example, a proposed solution has been to secure an insert in the gap using an adhesive. Often a foam insert has been used. While such foam inserts may limit entry of hair into the clipper housing for a period of time, experience has suggested them to be limited in effectiveness and service life. For example, some foam inserts tend to disintegrate after a period of use and to thereby re-open the gap for entry of hair cuttings. Also, disintegration may cause small portions of the foam to come loose, with these small portions potentially interfering with clipper operation in the same way that the hair cuttings do. Other types of foam inserts have been known to collect hair in the foam itself to the extent that clipper operation may be impaired.
Further, the adhesive used to secure an insert of the prior art can have a tacky surface that may disadvantageously attract and retain hair cuttings. This can be particularly troublesome when the adhesive surface gradually becomes exposed over time as the foam disintegrates. Also, the adhesives holding some inserts in place tend to weaken with age and use, with the result that the insert may come loose.
In addition to these problems, foam inserts have proven to be difficult to replace. Because the service life of the foam insert is often considerably shorter than that of the clipper, consumers must be relied upon to replace the inserts. This is disadvantageous because many users either do not have the expertise to replace the inserts or are not willing to go to the effort of replacing the inserts. As a result, clippers with foam inserts may have less than satisfactory operation and may suffer a shortened service life.
Finally, some clippers are intended to be used with different blade sizes and geometries. For example, a particular clipper may be designed to fit any of a plurality of interchangeable blade assemblies of different sizes. Each of these blades may have different geometries that result in the gap between them and the housing to be different. Known inserts are generally not able to effectively accommodate these different gap sizes.
Unresolved problems in the art therefore remain.